refactor(logo): encapsulate shared logo cache with AbortController cleanup

src/components/common/Logo.tsx

@@ -4,9 +4,9 @@
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
  */
 
-import { useEffect } from 'react';
+import { useEffect, useSyncExternalStore } from 'react';
 import { useTranslation } from 'react-i18next';
-import { useUIStore } from '@/stores/uiStore';
+import { ensureLogoLoaded, getLogoSnapshot, subscribeLogo } from '@/lib/logoCache';
 
 export function DefaultLogo() {
   const { t } = useTranslation();
@@ -31,19 +31,17 @@ export function DefaultLogo() {
 
 export default function Logo() {
   const { t } = useTranslation();
-  const logoUrl = useUIStore((s) => s.logoUrl);
-  const logoLoading = useUIStore((s) => s.logoLoading);
-  const fetchLogo = useUIStore((s) => s.fetchLogo);
+  const logo = useSyncExternalStore(subscribeLogo, getLogoSnapshot, getLogoSnapshot);
 
   useEffect(() => {
-    fetchLogo();
-  }, [fetchLogo]);
+    ensureLogoLoaded();
+  }, []);
 
-  if (logoUrl) {
-    return <img src={logoUrl} alt={t('logo.alt', 'Logo')} className="h-7 w-auto max-w-[220px] object-contain" />;
+  if (logo.status === 'custom') {
+    return <img src={logo.url} alt={t('logo.alt', 'Logo')} className="h-7 w-auto max-w-[220px] object-contain" />;
   }
 
-  if (logoLoading) {
+  if (logo.status === 'loading') {
     return <span className="h-7 w-[140px] block" aria-hidden="true" />;
   }
 

src/lib/logoCache.ts

@@ -0,0 +1,73 @@
+/*
+ * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <hello@stalw.art>
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ */
+
+import { getApiBaseUrl } from '@/services/api';
+
+export type LogoSnapshot = { status: 'loading' } | { status: 'custom'; url: string } | { status: 'default' };
+
+let snapshot: LogoSnapshot = { status: 'loading' };
+let objectUrl: string | null = null;
+let abortController: AbortController | null = null;
+let started = false;
+const listeners = new Set<() => void>();
+
+function emit(): void {
+  for (const listener of listeners) {
+    listener();
+  }
+}
+
+function revokeObjectUrl(): void {
+  if (objectUrl) {
+    URL.revokeObjectURL(objectUrl);
+    objectUrl = null;
+  }
+}
+
+export function getLogoSnapshot(): LogoSnapshot {
+  return snapshot;
+}
+
+export function subscribeLogo(listener: () => void): () => void {
+  listeners.add(listener);
+  return () => {
+    listeners.delete(listener);
+  };
+}
+
+/** Starts a single shared /logo fetch. Safe to call from every Logo mount. */
+export function ensureLogoLoaded(): void {
+  if (started) return;
+  started = true;
+  snapshot = { status: 'loading' };
+  emit();
+
+  abortController?.abort();
+  abortController = new AbortController();
+  const { signal } = abortController;
+
+  fetch(`${getApiBaseUrl()}/logo`, { signal })
+    .then(async (response) => {
+      const contentType = response.headers.get('content-type') ?? '';
+      if (response.ok && contentType.startsWith('image/')) {
+        const blob = await response.blob();
+        if (signal.aborted) return;
+        revokeObjectUrl();
+        objectUrl = URL.createObjectURL(blob);
+        snapshot = { status: 'custom', url: objectUrl };
+        emit();
+        return;
+      }
+      if (signal.aborted) return;
+      snapshot = { status: 'default' };
+      emit();
+    })
+    .catch(() => {
+      if (signal.aborted) return;
+      snapshot = { status: 'default' };
+      emit();
+    });
+}

src/stores/uiStore.ts

@@ -6,30 +6,17 @@
 
 import { create } from 'zustand';
 import { persist } from 'zustand/middleware';
-import { getApiBaseUrl } from '@/services/api';
 
 export type Theme = 'light' | 'dark';
 export type ColorTheme = 'stalwart' | 'ocean' | 'forest' | 'violet' | 'rose' | 'amber' | 'teal';
 export type Radius = 'rounded' | 'square';
 
-let logoAbortController: AbortController | null = null;
-let logoObjectUrl: string | null = null;
-
-function revokeLogoObjectUrl() {
-  if (logoObjectUrl) {
-    URL.revokeObjectURL(logoObjectUrl);
-    logoObjectUrl = null;
-  }
-}
-
 interface UIState {
   theme: Theme;
   colorTheme: ColorTheme;
   radius: Radius;
   sidebarOpen: boolean;
   activeSection: string;
-  logoUrl: string | null;
-  logoLoading: boolean;
 
   setTheme: (theme: Theme) => void;
   setColorTheme: (colorTheme: ColorTheme) => void;
@@ -37,9 +24,6 @@ interface UIState {
   toggleSidebar: () => void;
   setSidebarOpen: (open: boolean) => void;
   setActiveSection: (section: string) => void;
-  setLogoUrl: (url: string | null) => void;
-  setLogoLoading: (loading: boolean) => void;
-  fetchLogo: () => void;
 }
 
 function applyThemeClass(theme: Theme) {
@@ -87,49 +71,6 @@ export const useUIStore = create<UIState>()(
       radius: 'square',
       sidebarOpen: typeof window !== 'undefined' ? (window.matchMedia?.('(min-width: 768px)').matches ?? true) : true,
       activeSection: '',
-      logoUrl: null,
-      logoLoading: false,
-
-      setLogoUrl: (url) => {
-        revokeLogoObjectUrl();
-        if (url) {
-          logoObjectUrl = url;
-        }
-        set({ logoUrl: url, logoLoading: false });
-      },
-
-      setLogoLoading: (loading) => {
-        set({ logoLoading: loading });
-      },
-
-      fetchLogo: () => {
-        const { logoUrl, logoLoading } = get();
-        if (logoUrl !== null || logoLoading) return;
-
-        set({ logoLoading: true });
-        if (logoAbortController) {
-          logoAbortController.abort();
-        }
-        logoAbortController = new AbortController();
-
-        fetch(`${getApiBaseUrl()}/logo`, {
-          signal: logoAbortController.signal,
-        })
-          .then((response) => {
-            const contentType = response.headers.get('content-type') ?? '';
-            if (response.ok && contentType.startsWith('image/')) {
-              return response.blob().then((blob) => {
-                revokeLogoObjectUrl();
-                logoObjectUrl = URL.createObjectURL(blob);
-                set({ logoUrl: logoObjectUrl, logoLoading: false });
-              });
-            }
-            set({ logoUrl: null, logoLoading: false });
-          })
-          .catch(() => {
-            set({ logoUrl: null, logoLoading: false });
-          });
-      },
 
       setTheme: (theme) => {
         applyThemeClass(theme);